infection and response

• How do pathogens affect both plants and animals?

  They can infect both types of organisms
• What types of pathogens exist?

  Bacteria, viruses, protists, fungi
• How small are bacteria compared to body cells?

  About 1/100th the size
• How do bacteria make you feel ill?

  By producing toxins that damage cells
• What are viruses compared to bacteria?

  Much smaller than bacteria
• How do viruses replicate?

  Using the host cell's machinery
• What happens to the host cell after a virus replicates?

  The cell usually bursts, releasing viruses
• What are protists?

  Single-celled eukaryotes
• What shapes can fungi come in?

  Single-celled or hyphae structures
• How do hyphae cause disease?

  By penetrating skin and plant surfaces
• How can spores from fungi spread diseases?

  They can be spread to other organisms
• What symptoms do people with measles develop?

  Red rash and fever
• What serious complications can measles lead to?

  Pneumonia or brain inflammation
• How are most people protected against measles?

  Vaccination
• How can HIV be controlled?

  Using antiretroviral drugs
• What does HIV attack in the body?

  Immune cells
• What is the tobacco mosaic virus?

  A virus affecting many plant species
• What effect does the tobacco mosaic virus have on plants?

  Causes discolored mosaic patterns on leaves
• What is rose black spot?

  A fungal disease affecting rose plants
• What symptoms does rose black spot cause?

  Purple or black spots on leaves
• How can rose black spot be treated?

  Using fungicides and removing affected leaves
• What methods can reduce or prevent the spread of disease?

  • Being hygienic
  • Destroying vectors
  • Isolating infected individuals
  • Vaccination
• What is the role of the skin in the human body's defense system?

  Acts as a barrier and secretes antimicrobial substances
• What do the trachea and bronchi secrete to trap pathogens?

  Mucus
• What are the pros of vaccinations?

  • Control of communicable diseases
  • Eradication of smallpox
  • Prevention of epidemics with high vaccination rates
• What are the cons of vaccinations?

  • Not guaranteed immunity
  • Possible rare adverse reactions
• What is the difference between painkillers and antibiotics?

  Painkillers relieve symptoms, antibiotics kill bacteria
• Why are antibiotics ineffective against viruses?

  Viruses reproduce using host cells
• How can bacteria become resistant to antibiotics?

  Through mutations that confer resistance
• What happens to non-resistant bacteria when treated with antibiotics?

  They are killed by the antibiotics
• How can the development of resistant strains be slowed down?

  Avoid over-prescribing antibiotics
• What is aspirin used for?

  As a painkiller and to lower fever
• Late stage HIV infection, or AIDS, occurs when the body's immune system becomes so badly damaged it can no longer deal with other infections or cancers
• Salmonella food poisoning is spread by bacteria ingested in food, or on food prepared in unhygienic conditions
• Antibiotics, such as penicillin, are medicines that help to cure bacterial disease by killing infective bacteria inside the body
• Antibiotics cannot kill viral pathogens
• Painkillers and other medicines are used to treat the symptoms of disease but do not kill pathogens
• It is difficult to develop drugs that kill viruses without also damaging the body’s tissues
• New drugs are extensively tested for toxicity, efficacy and dose
• What does the nonspecific defense system do?

  Stops pathogens from entering the body